The subject matter disclosed herein relates to gas turbines and more particularly to a nozzle assembly for a gas turbine system.
Gas turbine nozzles are static components of a gas turbine configured to direct heat gas (˜2300° F.) in a hot gas path to the rotating portions of the turbine (i.e., to target rotational motion of the rotor). Though significant advances in high temperature capabilities have been achieved, superalloy components must often be air-cooled and/or protected with a coating to exhibit a suitable service life in certain sections of gas turbine engines, such as the airfoils In order to withstand high temperatures produced by combustion, the airfoils in the turbine are cooled. Cooling the airfoils presents a parasitic loss to the power plant as the air that is used to cool the parts has to be compressed but the amount of useful work that can be extracted is comparatively small. As such, it is desirable to cool these parts with as low flow of air as possible to allow for efficient operation of the turbine. The cooling air required can be reduced by using more advanced materials that can withstand the high temperature conditions in the flowpath. These materials tend to be orders of magnitude more expensive than the current super Nickel alloys, or can be very difficult to manufacture in the required shape of a conventional nozzle system. Materials such as ceramics and single crystal super alloys can increase gas turbine efficiency because their properties allow low to no cooling requirements. However, these materials can increase costs and often are unable to meet life requirements.